BMW E30 Differentials Guides

[AAM]

before u do anything... What the RPM in 5th gear when the speedo is showing 100kph???

will check that tomorrow.

thanks fabian.

 

[E28driver]

http://www.unixnerd.demon.co.uk/revs.html

All you had to do was ask....

 

[AAM]

before u do anything... What the RPM in 5th gear when the speedo is showing 100kph???

had a test run yesterday.

update : running at 100 kph in 5th gear, the tachometer reading was 3,600 RPM.

thanks fabian.

 

[AAM]

any comment ?

 

[Zoggee]

had a test run yesterday.

update : running at 100 kph in 5th gear, the tachometer reading was 3,600 RPM.

thanks fabian.

over revs. no top speed.

 

[AAM]

intends to change the rear diff.............

 

[fabianyee]

had a test run yesterday.

update : running at 100 kph in 5th gear, the tachometer reading was 3,600 RPM.

thanks fabian.

very high leh...
If I'm not wrong, ur gearbox should be running 1:0.81 5th gear.. When I was using 4.10 on the 318i, the RPM at 100kph is about 3,000rpm...

Join us for TT and see what's not right...

 

[AAM]

thanks fabian.

hope to meet you guys soon in one of those TT.

P/S : today manage to get hold 3.45 rear diff.

 

[AAM]

just for info : my E30 2.5L ( Auto ) - 100 kph at 3000 RPM ; E32 730iL ( Auto ) - 100 kph at 2200 RPM

never brave enough to test their top speeds - manage to touch 170 kph (before letting go the accel. pedal ) - can still go somemore ..........no complaint.

 

[Zoggee]

just for info : my E30 2.5L ( Auto ) - 100 kph at 3000 RPM ; E32 730iL ( Auto ) - 100 kph at 2200 RPM

never brave enough to test their top speeds - manage to touch 170 kph (before letting go the accel. pedal ) - can still go somemore ..........no complaint.

try search youtube my name and browse thru my vids. You'll find something interesting. Was running stock M20B25 diff 4.10.

 

[Fireblade]

try search youtube my name and browse thru my vids. You'll find something interesting. Was running stock M20B25 diff 4.10.

You still got the 4.10 diff? Am looking to replace mine cos its making noise.

 

[Zoggee]

You still got the 4.10 diff? Am looking to replace mine cos its making noise.

Sorry bro,the 4.10 is back onto my car. :smokin:

 

[AAM]

thanks fabian.

hope to meet you guys soon in one of those TT.

P/S : today manage to get hold 3.45 rear diff.

the 3.45 rear diff installed............will up date after test run.


p/s: gizmoz thanks for the stuff.

 

[gizmoz82]

the 3.45 rear diff installed............will up date after test run.


p/s: gizmoz thanks for the stuff.

]

ur welcome bro...

 

[AAM]

]

ur welcome bro...

contact me if got new stuff for E30, E34 n E32.

thanks

 

[AAM]

up date:

test run done this morning on Sban - P.D. highway with the 3.45 rear diff.

result : still the same - 100kph at 3600 rpm in 5th gear; and at 160 kph its already in the redline!

so sifus, what's wrong ?

thanks.

 

[fabianyee]

looks like u need to get at least a 3.15 rear diff... or a 2.97...
or is your tachometer is showing the correct RPM or not?

try holding in 1 gear (maybe 3rd) and rev all the way even past 6,000rpm and wait for the needle to bounce off the revlimiter.. See at what RPM the rev cut cuts in... stock rev cut should be 6500rpm.. if it can go far beyond 6,500rpm.. then u may be using the incorrect instrument cluster...

 

[teejay]

this is what happens when transplanting 'foreign' engine into the e30
the e30 meter cluster itsnt really compatible with all types of 'other engines'

i hear 3.5 engines use 2.91 differentials, the stoke of the big six is way off for the e30 electronics to digest.......

....just my thoughts, i maybe wrong though!!

 

[AAM]

looks like u need to get at least a 3.15 rear diff... or a 2.97...
or is your tachometer is showing the correct RPM or not?

try holding in 1 gear (maybe 3rd) and rev all the way even past 6,000rpm and wait for the needle to bounce off the revlimiter.. See at what RPM the rev cut cuts in... stock rev cut should be 6500rpm.. if it can go far beyond 6,500rpm.. then u may be using the incorrect instrument cluster...

fabian,

thanks. not sure about the reliability of the tachometer reading/instrument cluster compatability. will try to test as per your suggestion...........and let see where should I go from there.

 

[AAM]

Update: On the way to my first off. TT last nite - Sban- Sunway - Sban, did as what suggested by fabian.

My observation: RPM can still go beyond 6500 at 3rd gear ! ( not sure how high it will go- scared! ).

So sifus what is it - tachometer kaput or instrument cluster compatability issue ?

Or could it be the gearbox - close ratio ?


p/s: dont know the history of mods done by previous owners.


thanks.